Airplane-wing construction



emma Mu. 25,11930 --fUNrs-o STATES .PAT-:NT OFFICE,

TO H TOWLE, OI' DETBOIT, MICHIGAN, ASSI'GNOR TO THE TOWLE AIRCBAFTCOMPANY, OF DETBOIT, MICEIGAN, A. CORPORATION OF MICHIGAN .AIBPLANE-WINGCONSTRUCTI ON 4 Application filed July 5, 1929. Serial No. 875,972.

metal preferably Alclad duralumin with a thickness of .012" when usedfor a wing `measuring seven feet from the leading to the trailing edges.

B is the lower skin covering of the same material and thickness; C is astifl'ening sheet, also of the same material and thickness which is bentto form with the upper and lower skin covering A B a grder likestructure which combines maximum strength and stifness with minimumweight.

This corrugated sheet C has its corrugations flattened out along thelines where it comes in contact with the upper and lower skin A B asshown in Figure 2. At such places two reinforcing strips or stringers Dand E are provided. The inner stringer E is formed of a segment of aduralumin tube 1% inch outside diameter having a wall thickness of0.162". The outer stringer D is corrugated and has a wall thickness of.095". The corrugations'G in the stringers D give 3 lines of support tothe skin A B and these enable a thinner material to be used than wouldbe otherwise possib1e.

E conforms to theshape of C and D conforms to that of both C and A. Thesheet C is thus closely locked between the strips E and D but the stripD engages with the skin covering A at the bottom of the corrugationsin-v A at which point A C D and E are. all riveted together by means ofthe rivet F, Figure 2.

What I claim is 1. An all metal airplane wing comprising an upper andlower skin covering of corrugated sheet material having the corrugationsparallel to the line of fiight a stifenng sheet interposed between saidskins dividing' the space there-between intov triangular wedge shapeportions-said stiifening sheet having corrugations also parallel to theline of flight reinforcing st rin ers at the lines of contact betweenthe sti ening sheet and the outer skin.

2. Anl all metal airplane wing comprising an upper and lower skincovering of corrugated sheet material having the corrugations parallelto the line of flight a stifening sheet interposed between said skinsdividing the space there-between into triangular wedge s ape portions,said stifi'ening sheet having corrugations also parallel to the line offlight reinforcing' stringers at the lines of contact between thestiffening sheet and the outer skin, the corrugations of the stifi'eningsheet being removed where it engages with said outer skin. v

3. An all metal airplane wing comprising an upper and lower skn coveringof corrugated sheet material havin the corrugations parallel to the lineof fligt a stiifening sheet mterposed between said skins dividing thespace there-between into triangular wedge shape portions, said stifeningsheet having corrugations also parallel to the line of flight remforcingstringers between the stiffening sheet and the outer skin thecorrugation of the stilfening sheet being removed where it engages withsaid outer' skin a secsaid stringers so as to engage with and supi portsaid outer skin. A-

5. An all metal .air lane wing comprising an upper and lower s 'ncovering of corrugated sheet material having the corrugations parallelto the line of flight a stifi'ening sheet interposed between said skinsand folded so as to divide the space there-between into trifil angularwedge shape portions, said stifleningsheet havin corrugations' alsoparallel to the line of, 'ght, reinforcing stringers between thestifiening sheet and the outer skin, corrugations in said stringers soas to engage with and supp'ort said outer skin, an

ated sheet material having the corrigations parallel to the line offlight a stifi'ening sheet interposed between said skins and folded soas to (lived the space there-between into triangular wedge shapeportions said stiffening sheet having corrugations also parallel to theline of flight reinforcing stringers located within and supporting thefolds of the stifi'ening sheet.

In testimony whereof he afiixes his signature.,

TOM TOWLE.,

